In the paper, the effects of thermo-mechanical control process on microstructure and properties of oil country tubular goods by electrical resistance welding are analyzed. The TMCP parameters are optimized by Gleeble-1500 thermo-mechanical simulator, and industrial trial is carried out. The microstructures in the welded joints of original ERW OCTG are mainly composed of proeutectoid ferrite, pearlite and widmanstatten. In contrast, the welded joints of ERW OCTG treated by TMCP consist only of refined ferrite and pearlite. The higher low-temperature impact toughness and the better resistance to the grooving corrosion of the welded joints of ERW OCTG treated by TMCP could be attributed to removing welding residual stresses, homogenizing microstructure, eliminating porosity and refining grain. TMCP facilitates the performance optimization of welded joints so that the quality of the finished product can be improved.